The effect of preoperative total parenteral nutrition on surgery outcomes

The effect of preoperative total parenteral nutrition (TPN) on morbidity and mortality was studied in medical records of discharged surgical patients. Patients were classified into two groups on the basis of their ability to meet established criteria for malnutrition and the use of preoperative or postoperative TPN. The control group consisted of 44 patients who received TPN only after surgery or for less than 5 days preoperatively. The experimental group consisted of 26 patients who received treatment for at least 5 days before surgery and/or after surgery. Nutrition parameters measured included serum albumin, total lymphocyte count, hemoglobin, weight, and percent weight loss. Major septic complications (MSC) considered were intra-abdominal sepsis, wound dehiscence, septicemia, and pneumonia. Other complications included respiratory failure, congestive heart failure, fistulas, urinary tract infection, shock, and death. The experimental group showed improvements after surgery in the nutritional parameters listed and had a lower incidence of morbidity and mortality. Deficits in serum albumin, total lymphocyte count, and weight losses greater than or equal to 10% have been significantly (p less than .01) linked to the incidence of MSC. MSC also has been more frequently noted among patients who did not have TPN prior to surgery and who died following surgery. Therefore, preoperative TPN does appear to make a difference in the outcome of surgery.     

A cost-utility analysis of the home parenteral nutrition program at Toronto General Hospital: 1970-1982

We performed an economic evaluation of a home parenteral nutrition (HPN) program by measuring the incremental costs and health outcomes for a cohort of 73 patients treated at our institution from November 1970 to July 1982. Over a 12-year time frame, we estimate that HPN resulted in a net savings in health care cost of $19,232 per patient and an increase in survival, adjusted for quality of life, of 3.3 years, compared with the alternative of treating these patients in hospital with intermittent nutritional support when needed. This result was sensitive to assumptions made about the cost of the alternative treatment strategy. When these assumptions were most unfavorable to the HPN program, we estimated that HPN resulted in incremental costs of $48,180 over 12 years, $14,600 per quality-adjusted life-year gained. We conclude that the cost-utility of HPN compares favorably with other health care programs, when HPN is used to treat patients with gut failure secondary to conditions such as Crohn's disease or acute volvulus. Since only one patient with active malignancy was enrolled in our HPN program, these results should not be extrapolated to patients with active malignancy.     

Economics of total parenteral nutrition

Better data on the effectiveness of TPN are required, along with good costing data on the procedure and its benefits. The Veterans Administration Cooperative Trial on Perioperative TPN will be collecting such data. In this randomized trial, data are being collected on both the effectiveness of the procedure and the costs, direct and indirect, of the procedure and its consequences. Similar studies for other indications will help to establish fully the economics of TPN. As Steinberg and Anderson point out, it is important to remember that the absence of evidence that a procedure is not cost-effective does not imply that it is not cost-effective. As this review has shown, the cost-effectiveness of TPN has been evaluated for only a few indications. The results of more extensive cost-effectiveness analyses remain to be seen.     

Precipitate analysis from an indwelling total parenteral nutrition catheter

The composition of a precipitate obtained from a silastic right atrial catheter was determined. The precipitate was collected and washed with deionized water thoroughly before subjecting portions of it to organic and inorganic analysis. Inorganic analysis was conducted using scanning electron microscopy and x-ray spectroscopy for sodium, aluminum, silicone, sulfur, chlorine, and calcium. Phosphorus analysis was conducted by a commercial laboratory. Organic analysis was conducted by thin layer chromatography with cholesterol, phosphatidyl serine, phosphatidyl choline, phosphatidyl ethanolamine, and sphingomyelin as standards. Silicone, calcium, and phosphorus and three organic compounds, which could not be conclusively identified, were found. The precipitate was most likely calcium phosphate intermixed with silicone oil lubricant and residual total parenteral nutrition (TPN) solution. This formed in the catheter at body temperature probably due to incomplete catheter flushing.     

Ambulatory home total parenteral nutrition

Ambulatory total parenteral nutrition (TPN) at home was used in 85 patients within a 6-yr period. Indications include severe malabsorption, fistulas, anorexia nervosa, and malignancies. The median duration of home TPN (HPN) was 67 days (range: 30-4,155 days). HPN duration for patients with benign diseases was longer [357.12 days (range: 30-4,155 days)] than for cancer patients [93.54 days (range: 30-421 days)]. Under HPN, patients gained a good nutritional status with an increase of total protein (p less than 0.001) and serum albumin levels (p less than 0.001). Weight gain was also significant (p less than 0.001). The rehospitalization rate was low (7.8%), but it was higher when HPN lasted for more than 3 months (10.87% +/- 1.58%) compared with short-term HPN (5.69% +/- 1.25%). Metabolic complications were unusual, and rehospitalization was related to the oncological treatment and/or infectious complications. Therefore, ambulatory HPN is a nutritional support that can significantly improve the life of patients with alimentary failure. Moreover, HPN allows significant cost savings compared to the alternative of prolonged hospitalization.     

Hepatic complications of total parenteral nutrition

Elevations in serum hepatic enzyme levels and alterations in hepatic morphology have been noted in patients on total parenteral nutrition, in some cases progressing to fatal hepatic failure. Various factors such as toxins, inappropriate substrates, overfeeding, deficiency states, and gut hormone alterations have been implicated. It would appear that the tailoring of nutritional support to meet patient needs and the maintenance of normal gut integrity will be of increasing importance in reducing the incidence of this potentially fatal complication.     

Ethical issues in total parenteral nutrition

Although a number of ethical issues have been identified with TPN use, the most pressing issues are equitable access to the technology; potential injustices toward other members of society because of the cost of the technology; quality of life issues, including prolongation of life; and decision making for TPN use. Empirical data on the factors that influence access to the technology and on the current utilization of TPN in elderly populations are needed to assess the issue of equitable access to the technology. In addition, the effects of the technology's cost on access need to be evaluated carefully. The decision-making process in the use of TPN and the relation of quality-of-life judgments to such decisions need further study and evaluation. In addition, factors that influence the decision to withdraw TPN also need to be identified and studied. Adequate ethical assessment of any technology relies in part, on empirical studies in the field, the sophistication of the ethical literature, and the careful delineation of the conceptual and methodologic issues associated with a particular technology's use. To the extent that these aspects can be addressed in the use of TPN, there is reason to believe that an adequate ethical assessment of the technology will be made, but such an assessment is not yet available.     

Folic acid and total parenteral nutrition

The stability of folic acid in a variety of solutions used for parenteral nutrition has been determined over a 2-wk period. Provided that the acidity of the solution remains above pH 5.0 the folate, in the concentrations usually used for parenteral nutrition, will remain stable in solution, and all of the folate added to the solution will be delivered to the patient. The applicability of this in vitro work to a group of patients requiring parenteral nutrition was assessed, in order to determine a suitable dose. A dose of 0.2 mg of folic acid daily was inadequate to meet the requirements of these patients. In contrast a dose of 1.2 mg daily for 7 days was sufficient to cause an increase in the serum folate concentration.     

Vitamin status during total parenteral nutrition

Plasma concentrations of vitamins A and E, serum and erythrocyte folic acid, serum B12 and erythrocyte enzyme activations (to assess vitamins B1, B2 and B6 status) were measured at the start and finish of 39 courses of total parenteral nutrition (TPN). The daily regimen was standard. Plasma vitamin A, E, and folate concentrations and vitamin B6 status improved significantly during TPN. Three patients developed low levels of vitamin A and two patients developed high transketolase activations (B1 depletion) during therapy. The adequacy of vitamin replacement and the monitoring of vitamin status during TPN is discussed.     

An experience with total parenteral nutrition in children.

Total parenteral nutrition has been used in the treatment of more than 100 children with gastrointestinal illnesses, including 90 under the age of 6 months. The incidence of complications has been reduced markedly as experience was acquired. Total parenteral nutrition has been especially valuable in patients with intractable diarrhea syndrome and it has been used successfully in the management of infants with overwhelming systemic infections.     

Preventing hypophosphatemia during total parenteral nutrition

Phosphate supplementation during total parenteral nutrition (TPN) is essential to prevent hypophosphatemia but individual phosphate requirements vary. We reviewed 68 courses of TPN in 61 patients to determine the incidence of hypophosphatemia and to identify factors which indicate a need for additional phosphate supplementation. Eight (12%) patients were hypophosphatemic before initiation of TPN. Sixty (88%) patients were normophosphatemic when TPN was initiated and 25 (42%) became hypophosphatemic. Of these 60 patients, 20 (38%) of 52 patients became hypophosphatemic when supplemented with 13.6 mM phosphate/liter or more, whereas five (63%) of eight patients became hypophosphatemic when supplemented with only 6.8 mM phosphate/liter TPN fluid. More hypophosphatemic patients required insulin during TPN (48 vs 26%), were initially hyperglycemic (24 vs 9%), were alcoholic by history (24 vs 11%), had evidence of chronic weight loss (64 vs 46%), and had a history of recent diuretic (40 vs 23%) or antacid therapy (56 vs 43%). Hypophosphatemia occurs frequently after initiation of TPN therapy despite phosphate supplementation. Provision of 13.6 mEq phosphate/liter prevents hypophosphatemia in most patients. However, patients who are hyperglycemic, require insulin during TPN, or have a history of alcoholism, chronic weight loss, or chronic antacid or diuretic therapy may require greater supplementation to prevent the development of hypophosphatemia. Chronically malnourished patients require a slower initial rate of infusion as well.